Spin-dependent electron transport mechanisms are known to have interesting applications in solid-state devices. In particular magnetic topological solitons, which may also be referred to as topological defects, may be used as elemental information carriers. The topological solitons may particularly relate to ferromagnetic topological solitons, or anti-ferromagnetic topological solitons.
Topological defects are particularly stable against small perturbations and decay, for example because such defects are homotopically distinct from the vacuum state. Therefore, the use of topological solitons as bit-encoding information carriers in memory devices can allow for low power consumption, robustness to noise and high transfer speeds. Moreover, logic circuitry could be manufactured which operates directly on streams, e.g. bitstreams, of topological solitons. For example, ultra-high density memory, e.g. a magnetoresistive random access memory, and logic devices may be achieved in accordance with certain embodiments.
An example of ferromagnetic topological solitons which can be used as elemental information carrier is a spin wave or magnon, e.g. a propagating disturbance in the ordering of a magnetic material, forming a boson mode of the spin lattice. Another example is a skyrmion, e.g. a two-dimensional magnetic skyrmion having a chiral nature, e.g. having a non-zero, integer topological charge. Yet another example is a domain wall, e.g. an interface between magnetic domains.
It is known in the art that magnetic topological solitons, e.g. skyrmions, can be generated and manipulated using spin-polarized currents and spin-transfer torques.
However, a need exists in the art for an easy and efficient conversion of information encoded by a magnetic topological soliton to a conventional electronic encoding, e.g. a need exists for a simple and efficient electrical detection of magnetic topological solitons, e.g. such as skyrmions.